Reliability of MDCT measurements of pulmonary vein ostial diameter and distance to first bifurcation: an interobserver study comparing radiologists with a semiautomated software.

The purpose of this study was to evaluate agreement between radiologists and semiautomated software measurements of pulmonary vein ostial diameters and distance to the first bifurcation. Computed tomography (CT) examinations of the thorax were retrospectively reviewed in 50 consecutive patients. The pulmonary vein ostial diameter and distance to the first bifurcation of the four major, and the middle lobe pulmonary veins, were measured independently by two experienced cardiothoracic radiologists, and using CardEP semiautomated software. The two measurement methods were compared. Analyses were performed using a Bland-Altman test. There is no significant variation between readers or between readers and the software in pulmonary vein ostial diameter measurements for the four major pulmonary veins. There is significant variation between the first reader (P = 0.03) and between the second reader and the software (P = 0.01) in vein diameter measurements for the middle lobe vein. And, also between the second reader and the first reader for the right inferior (P = 0.02) and left inferior (P = 0.02) pulmonary vein distance to first bifurcation, and between the second reader and the software for the right inferior (P = 0.01) and left inferior vein (P = 0.02) distance to first bifurcation. There is good interobserver agreement when measuring the major pulmonary vein diameters. Measurements of distances to first bifurcation were less reliable across readers and the readers and the semiautomated software.